It is well known in the art to preserve harvested produce with ice for the period of time the produce is en route from the field to the marketplace. It is also well known that the quality of the produce when it arrives at the marketplace is affected by the speed with which it is chilled at the outset from field temperature to the desired transportation and holding temperature.
The first use of icing as a means of preservation involved placing ice in each shipping container or box as it was filled, or later at a central point as the containers were readied for loading on the transport vehicle. This laborious manual procedure has been supplanted by an automated procedure which is capable of icing more than one container at a time.
U.S. Pat. No. 4,484,448 to Crabb describes an ice injector which is capable of accepting pallets loaded with a plurality of containers of produce and injecting a slurry of ice and water into all containers simultaneously. The patent teaches that the ice injector may be loaded, operated and unloaded in a few minutes, saving time over the previous practice of manually icing individual containers one at a time.
In the present market, the consumer chooses produce using both quality and price criteria. The quality is directly affected by the rapidity with which the produce is received in the marketplace after harvesting. Price is affected to a great extent by the economy with which the numerous required actions between harvesting and presentation to the consumer are performed.
The ice injector disclosed in the patent referred to above operates at a speed determined by the slowest step in the action sequence. Typically, loading and unloading are done with a fork lift which loads and unloads one pallet at a time from the ice injector. The icing step occurs at a set time period determined by the number of containers on the pallet and the size of the containers. This step is relatively inflexible and cannot be speeded up without endangering the produce within the containers, hereafter referred to as boxes. The slowest steps in the sequence, and those most likely to be improved, are the in-feed operation and the unloading step.
The ice injector is provided with means to capture and recycle excess chilled water that drains from the boxes on the pallet. However, the pallet is not permitted to remain in the ice injector for more time than is necessary to inject the ice water slurry into the boxes on the pallet. Consequently, as the pallet is removed from the ice injector, excess chilled water is still draining from the boxes and is not captured for recycling because it spills onto the ground and goes to waste. Collection and reuse of the excess chilled water would provide economies in the cost of the water and the cost of chilling it, but permitting the pallet to dwell in the ice injector until drainage is complete would take too much time.
The present invention provides a way to expedite the loading and unloading activities so that the ice injector may be operated at peak efficiency in time and energy consumption and provide nearly 100% water recycling at the same time.
The present invention also allows the use of multiple-pallet handling equipment for simultaneously loading or unloading of more than one pallet, further enhancing the system operating efficiency.